Earth boring drills



Feb. 5, 1957 EARTH BORING DRILLS Filed sept j 2o, 1954 FIGB 6 4 FIG. 4. f7

I3 M m /II L Q 1 -TLT i ',5 `8 l Il lx 'E INVENTOR.

CHARLES 'W. KANDLE m JM Attorneys cf w. KANDLE 2,780,439 v United States Patent O fr'ce 2,780,439 EARTH BORING DRrLrs charles wiiliam'xandle, chicago, m. Application September 20, 1954, Serial No. 457,027 s claims. (ci. zes-69) plurality of socket members are xedly secured in spaced relation in the outer periphery of the spiral screw flight for individually supporting a removable cutting member.

'Each socket member is provided with a circular socket openingand a slot extending across the forward face of Each corresponding cutting member is comprised Aof a circular shank which extends into the opening of the. socket member and a body portionfor carrying a cutting bit offset from the axis of the shank which seats in the slot' of the socket member and secures `the cutting lmember against rotation. Pin means extend- `ing through the socket member and shank of the cutting 4member removably secure the members together.

4The drawings furnished herewith illustrate the best mode of carrying out -the invention as presently contem- 'A plated and set forth hereinafter.

.In the drawings: i Figure 1 lis a perspective view ofthe earth boring drill of the invention showing the cutter elements spaced on the tapered spiral screw flight;

Fig. 2 is anenlarged perspective view showing a cutting element in its socket secured to the screw llight and with the contourof the hole formed by the drill indicated by a Idotted line;

Fig. -3 is an end elevation of a cutting element removably secured in its socket', and

Fig. 4 is a side elevation partially in section showing th'e cutting element in its socket.'

In carrying out the invention an earth boring drill adapted to be driven rotatably is provided with a tapered shaft 1 having a relatively smaller diameter at the forward or penetrating end thereof and carries the cutting tip 2 forwardly thereof. The shaft 1 is provided with the correspondingly tapered spiral screw night 3 to form an earth moving conveyor. The spiral screw flight 3 carries a plurality of spaced angularly disposed socket members 4 in the outer periphery therefor for individually receiving and removable cutting members 5.

According to the invention, each socket member 4 is generally cylindrical and is provided with a at chordal surface 6 and a circular socket opening 7 extending axially therethrough. A slot 8 is provided across the forward face of each socket member 4 generally normal to the chordal surface 6 of the member.

A plurality of spaced generally circular cavities 9 are provided in the outer periphery of the screw flight 3 over the length thereof for individually receiving socket .to secure the cutting member against rotation.

2,780,439 Patented Feb. 5, 1957 2 f Y members 4. Each socket member 4 extends axially through the screw Hight 3 and is disposed atan angle and Welded within the cavity with the chordal surface 6 facing outwardlyof the drill and flush with the outer periphery of the screw flight 3. The angle of the socket member welded in place is such that the slotted or forward end facing in the direction of the drilling extends outwardly respecting the periphery of the drill.

The cutting member 5 is received forwardly by each socket member 4 and is removably secured therein. Each cutting member 5 is comprised of a rearwardly extending shank 10 which is received in the socket opening 7 of a corresponding member 4. The body portion 11 of each cutting memberS extends forwardly from the respective shank 10 and is formed integrally with the shank and received within slot 8 of the socket member The cutting bit 12 is carried forwardly by body portion 11 and is secured therein as by brazing and is offset from the axis of shank 10. The cutting edge of bit 12 is parallel to slo't 8 so as to be angularly disposed with respect to chordal surface 6 and extends outwardly beyond surface 6.

Each cutting member 5 is secured within the respective socket member 4 by means of a cotter pin 13 extending through transverselyaligned .holes provided in each corresponding socket member and shank 10, to permit removal of each member for sharpening and replacement.

The arrangement of cutting member 5 within socket members 4 and their combined arrangement within screw ilight 3 provides the cutting bit 12 with the desired cutting angle. The axis of each socket member 4 extends forwardly outward so that when drilling vertically the cutting edge of bit 12 ,secured therein is disposed at any inwardly sloping angle with respect to a horizontal plane. Each bit 12 therefore cuts an angularly disposed ledge, the inner edge of which is closer to the bottom of the crater being cut than is the outer edge. The axis of Isocket member 4 is also angularly disposed with respect to shaft 1 to provide the cutting blade with a positive front rake. As the cut material is lifted by the leading face of bit 12 the angularity of the bit with respect to chordal surface 6 flush with the outer periphery of screw lflight 2 provides a side rake angle for carrying the cut material inwardly onto the earth moving screw flight. The invention provides a spiral drill capable of cutting ,through hard materials such as ysandstones and shales.

`Rock formations encountered in drilling operations are frequently characterized by undefined differences in density over short distances. With cutting heads spaced axially over the length of the screw flight and therefore through one or more density variations of such materials y an average number of different cutters are always in harder or softer rock portions. This averages the cutting resistance encountered to correspond with the maximum speed of drill rotation and pressure applied to advance the drill. The rugged construction and readily replaceable drill bit insures that machine down-time for the drill of this invention will be kept to an absolute minimum.

Various modes of carrying out the invention are contemplated as within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

l. In an earth boring drill, a shaft, a tapered spiral screw night carried by the shaft and extending from the forward end thereof with the relatively smaller diameter disposed forwardly, a plurality of socket members xedly secured in spaced relation in the outer periphery of the screw flight, each socket member being provided with a socket opening forwardly, a plurality of cutting members each having a shankportion and a cutting'bit offset from the axis of the shank,the shank of each cuttingvmember tting within a socket opening and being secured against rotation within the socket member, each cutting bit extending beyond the outeradjacentedge of the screwfight and angularly withl respect to theshaft witha positive front rake, and means to removably secure the shank of eachL cutting member within the socket opening to secure' the same in operative relation and allow replacement of the cutting member,

2. in an earth drill for hard rock, shale and the like, a shaft having a tapered screw ight extending from the forward end of= the shaft, said flight having av spirally formed outer edgey with' the relatively smaller diameter at the forwardv end of the dril1,.a series of socket mem'- bers fixed within notches formed in the outer margin. of said ight, eachmemberhaving a circular socket hole extending therethrough-.and abutment means on the forward 'face of the member, a series of cutters' individually having a circular shank and a cutting tooth oifset from the axis of said shank, the shank of each cutter fitting within the socket hole of a corresponding socket member with the cutter secured against l*rotation by the abutment means, each cutter tooth extending beyond the radial dimensions of the adjacent edge of the drill flight and angularly with respect to the drill shaft' with a positive front rake, and a removable pin extending through corresponding holes in saidr member and cutter shank to secure the same in assembled operative relation and allow replacement and sharpening of the cutter.y

3. In an earth boring drill a shaft, a tapered spiral screw ight carriedby they shaft and extending from the forward end thereof with'thezrela'tively smaller diameter disposed forwardly, a plurality of socket members xedly secured in spaced relation in the outer periphery of the screw ilight, cach socket member being provided with a circular socket opening therethrough and a` slot extending across the forward face ofthe member, azplurality of cutter members each having a circular shank and a cuttingtooth oset from the axis ofsaid shank, the shank of each cutter member fitting within the vsocket opening of a corresponding socket member with the cutter member partially' disposed within said slot so as to be secured against rotation, each cutting tooth extending beyond the outer adjacent edge loi" the screw flight and the socket memberholdingthe same andangularly with respectto the shaft with a positive. front rake, and removablepin means extending through aligned holes insaid members to secure the same in operative relation and allow replacement of the cutter member.

4. In an earth boring drill, a shaft, a tapered spiral screw flight forming an earth moving conveyor carried by the shaft and extending fromthe forward end thereof with the relatively smaller diameter disposed forwardly, a plurality of generally cylindrical socketrnernberseach having an outwardly disposed chordal surface and a circular socket opening therethrough and a slot extending across the forward face ofV themember angularly'to the chordal surface, said socket members being welded within notches provided in spaced relation in the screw ight with the chordal surfacesdisposed angularly ush with the outer periphery thereof, a plurality of cutter members each having a circular shank and a cutting bit offset from the axis of said shank, the shank of each cutter member itting within the socket opening of a corresponding socket member with the cutter member partially disposed within'. said slot so as to besecured against rotation, each cutting bit extending parallel to the slot and each bit being disposed' angularly'tothe chordal surface to provide a side rake'to carry the loosenedmaterial inwardly to the earth moving conveyor, each bit extending outwardly beyondv` the chordal surface and angularly with respect to the shaft to provide a positive front rake, and a removable pin extending through aligned holes in said member to secure the same in operative relation and allow replacement of the cuttermember.

5. In anI earth boring drill, a shaft, a taperedspiral screw flight forming an earth moving conveyor carried bythe shaft' andextending from the forward end thereof withY the relativelyfsmaller diameter disposed forwardly, af plurality'v of generally cylindrical socket members each having an outwardlydisposed chordal surface and a circular socket opening therethrough and aslot extending across the forward: face ofthe member angularly to the chordali sur-face, said socket members beingqsecured as by welding tothe flight within the notches providedin spaced relation in the ight and with the chordal `surfaces disposed angularly-'with respect to the shaft and ush with the outer peripheryv of thescrew ight, a plurality of cutter members;each..having. a circular shank and a cutting edgenormal :to the shank and offset from. the axis of i said shank, v.the shank. of each cutter member fitting withinrthey socket opening of a` corresponding socket member with the cutter member partially disposed. ywithin said-slot so asy to be secured against rotation, each cuttingedge beingi angularly disposedby the respective socket member to cut a conical' edge each cutting edge being.. disposedfparallelto the slot and angularly to the chordal surfaceof the socket members to provide a side rake to carry theloosened material inwardly to the earth moving conveyor, and each cutting edgeextending outwardly beyond the chordal surface and angularly with respect to the shaft to provide a positivefront rake, and a removablepin extendingthrough aligned 'holes in said members to.secure the same in operative relation and allow replacement of the cutter member.

References Cited in the le of this patent UNITED STATES PATENTS 1,859,717 Rutrle May 24, 1932 2,594,261 Henning Apr. 22', 1952 FOREIGN PATENTS 625,362 Great Britain June `27, 1949 

